I have attached a patch that allows an additional optional field to be added to the form definition, see excerpt from TWikiForms:

• An optional additional column "Mandatory" may be entered at the end of the definition of a WebForm.
  • If a row has a non-empty content (strictly speaking, not equivalent to Boolean false) in this cell, the form specified by this WebForm cannot be saved if the corresponding field does not have a value specified.
  • Otherwise, i.e., if the cell is empty or absent, no validation is performed when attempting to save a topic containing such a form.

Example: Modified WebForm from the TWiki.Know web

| *Name* | *Type* | *Size* | *Values* | *Tooltip message* | *Mandatory* |
| Know.TopicClassification | select | 1 | Know.NoDisclosure, 
  Know.PublicSupported, Know.PublicFAQ | blah blah... | |
| Know.OperatingSystem | checkbox | 3 | Know.OsHPUX, Know.OsLinux,
  Know.OsSolaris, Know.OsWin | blah blah... | |
| Know.OsVersion | text | 16 | | blah blah... | Yes |

Name	Type	Size	Values	Tooltip message	Mandatory
TopicClassification	select	1	NoDisclosure, PublicSupported, PublicFAQ	blah blah...
OperatingSystem	checkbox	3	OsHPUX, OsLinux, OsSolaris, OsWin	blah blah...
OsVersion	text	16		blah blah...	Yes

A topic containing this WebForm can only be saved if the OsVersion field is filled in.

When a topic containing this form is being edited, mandatory fields are marked with a red asterisk and a legend appears at the bottom (only if mandatory fields are present). If a user does not enter data for such a mandatory field, upon entering preview an oops is raised and saving is prevented. The user is asked to return to continue editing the topic.

Warning: The attached patch is against the Athens release. I need to still port it to the Beijing release.

-- ThomasWeigert - 13 Apr 2003

I've already extended forms to have an option field. This could certainly be used to make some field as manditory. Additionally a plugin hook could be added so that more general validation could be done by a plugin. The only use of the option field at present is to make an entry as a setting.

-- JohnTalintyre - 13 Apr 2003

Thanks for pointing this out. I'll check into how you are using the "option field", when I convert this to work with the Beijing release. Note that the main work in the attached patch is in enforcing that mandatory fields are filled in.

A more general validation would be useful, albeit I cannot see how that could be independent of the application, so we would end up having to write perl code at the user level (except for very simple type checking of entered data).

-- ThomasWeigert - 14 Apr 2003

See UsingFormsForSettings for the new field. Note that this is part of the CairoRelease. One thing you could validate is a date, I'm sure there are other generic things, plus as you say, the ability to do things at a Perl level e.g. deal with changes in workflow, which could affect what is manditory.

-- JohnTalintyre - 14 Apr 2003